Heat maps can be created from point layers that allow configuration of symbology. This includes ArcGIS Server feature layers, Spatial Data Service layers, geoRSS layers, and graphics layers. For more information on the different layer types and their capabilities, see Layer types.
About heat maps
When a layer contains a large number of point features, showing each feature individually on the map is often not useful. In this scenario, point features often overlap, making it difficult to distinguish between features. Even when they do not overlap, it is usually difficult or impossible to visually extract meaningful information when hundreds or thousands of points are shown all at once.
One approach to resolving this issue is to generate a heat map. A heat map represents the geographic density of point features on a map by using colored areas to represent those points. The areas will be largest where the most points are concentrated together. Also, areas of high density, or hot spots, will be symbolized with the color chosen to represent "hot" areas. While heat maps in general can also incorporate one or more attributes into how they are calculated, heat maps in the ArcGIS Viewer for Silverlight only account for geographic location. Consequently, heat maps in the Viewer provide an effective way to visualize where the point features in a given layer are most concentrated.
Creating a heat map
To create a heat map, complete the following steps:
- Choose the point layer on the Configure Layers panel that you would like to generate a heat map from.
- Right-click the layer and click Configure. Alternatively, click the Configure button at the bottom of the panel:
- On the Configuration panel, expand the Heat Map group and click Add Heat Map: A heat map is calculated and automatically added to the map. The heat map also becomes the selected layer, so the Intensity and Color Scheme buttons will be enabled.
- Click the Intensity button to open the intensity slider. Use the slider to increase or decrease the heat map's intensity.
- Click the Color Scheme button to show a list of color gradients that can be applied to the heat map layer. To apply a gradient to the layer, select it from the list.